As the number of digital communication services offered by communication service provides increases, so too does the importance of switching apparatuses that support both analog and digital terminals. The increasing use of the medium of the World Wide Web and coupled with increase in the importance of this medium creates a growing need for communication users of even comparatively small and medium-sized switching apparatuses to have access to the World Wide Web. The existing need among communication users to connect personal computers (PCs) to telephone systems is currently met, for example, by Siemens AG with a private branch exchange (PBX) realized in the form of a plug-in card for a personal computer. Via this telephone system it is possible to drive digital terminals, to make telephone calls with PC support, and to perform the administration and billing management of the telephone system on the PC. These capabilities are described, for example, on the World Wide Web at the address: “http://www.siemens.de/ic/networks/pn_neu/km/hicomint/paar2. htm”
One disadvantage of existing systems is the necessity of opening the housing of the personal computer in order to install the plug-in card. Another advantage is that software administration measures are required to ensure reliable operation of the private branch exchange (i.e., the need to continually update the administration and interface software to ensure compatability with new versions of PC operating systems.
An object of the present invention is, therefore, to provide an external switching apparatus with Integrated Services Digital Network (ISDN) access from PC environments.